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27 i5 ijaet0511509 measurement of carbonyl emissions copyright ijaet
 

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The research work is divided into (1) a portable sample collection technique (2) developing a suitable catalyst combination and (3) manufacturing a catalytic converter with novel design. Taking into ...

The research work is divided into (1) a portable sample collection technique (2) developing a suitable catalyst combination and (3) manufacturing a catalytic converter with novel design. Taking into account the hazards of aldehydes in ambient air, and carbonyl emissions compounds, an effort has been made to investigate the carbonyl compounds and measure their concentrations for diesel engines using Bio Ethanol (BE)-diesel fuel. From the said analysis, development of a potential catalytic converter is envisioned in order to reduce these emissions along with carbon monoxides, hydrocarbons and nitrogen oxides. Catalytic converter is specially manufactured for reduction of carbonyl emissions from the BE-diesel fuelled engine and its comparison and its integration with conventional three way catalysts is discussed. The retention time of the raw sample peak is comparable to the retention time of formaldehyde standard solution. Solitary formaldehyde peak is obtained. Peaks of acetaldehyde and acetone are not obtained due to their lower concentrations than the limit of detection, at the given loading condition. Retention time of each arrangement is close to that of formaldehyde standard. It is observed that CO, HC and NOx conversion efficiencies remained constant irrespective of combination with specially designed ZrO2 catalyst. Formaldehyde concentration obtained for one ZrO2 catalyst sample is significantly lower than raw emissions. Added ZrO2 catalyst showed further reduction. Thus, with optimum loading and surface area improvement methods, better results are achievable. Pt-Rh catalyst shows better carbonyl reduction than Pd-Rh catalyst. However, each of the three way catalysts is less efficient than ZrO2 catalyst. ZrO2 catalyst used in series with Pt-Rh catalyst shows the highest percentage reduction in formaldehyde concentration. Pt-Rh catalyst pair is effective in CO mitigation than Pd-Rh pair. The percentage reduction for HC and NOx is comparable for both. Pt-Rh also depicts better carbonyl reduction ability. ZrO2 is a better choice than noble metals in terms of availability and cost. Moreover it features a selective nature towards oxidation of aldehydes. Thus, Pt-Rh in combination with ZrO2 becomes technologically effective and economically viable choice.

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    27 i5 ijaet0511509 measurement of carbonyl emissions copyright ijaet 27 i5 ijaet0511509 measurement of carbonyl emissions copyright ijaet Document Transcript

    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963 MEASUREMENT OF CARBONYL EMISSIONS FROM EXHAUST OF ENGINES FUELLED USING BIODIESEL-ETHANOL-DIESEL BLEND AND DEVELOPMENT OF A CATALYTIC CONVERTER FOR THEIR MITIGATION ALONG WITH CO, HC’S AND NOX.Abhishek B. Sahasrabudhe1, Sahil S. Notani2 , Tejaswini M. Purohit3, Tushar U. Patil4 and Satishchandra V. Joshi 51,2,3,4 Student, B.E., Deptt. of Mech. Engg., Vishwakarma Institute of Technology, Bibwewadi, Pune, Maharashtra, India. 5 Prof., Deptt. of Mech. Engg., Vishwakarma Institute of Technology, Bibwewadi, Pune, Maharashtra, India.ABSTRACTThe research work is divided into (1) a portable sample collection technique (2) developing a suitable catalystcombination and (3) manufacturing a catalytic converter with novel design. Taking into account the hazards ofaldehydes in ambient air, and carbonyl emissions compounds, an effort has been made to investigate thecarbonyl compounds and measure their concentrations for diesel engines using Bio Ethanol (BE)-diesel fuel.From the said analysis, development of a potential catalytic converter is envisioned in order to reduce theseemissions along with carbon monoxides, hydrocarbons and nitrogen oxides. Catalytic converter is speciallymanufactured for reduction of carbonyl emissions from the BE-diesel fuelled engine and its comparison and itsintegration with conventional three way catalysts is discussed. The retention time of the raw sample peak iscomparable to the retention time of formaldehyde standard solution. Solitary formaldehyde peak is obtained.Peaks of acetaldehyde and acetone are not obtained due to their lower concentrations than the limit ofdetection, at the given loading condition. Retention time of each arrangement is close to that of formaldehydestandard. It is observed that CO, HC and NOx conversion efficiencies remained constant irrespective ofcombination with specially designed ZrO2 catalyst. Formaldehyde concentration obtained for one ZrO2 catalystsample is significantly lower than raw emissions. Added ZrO2 catalyst showed further reduction. Thus, withoptimum loading and surface area improvement methods, better results are achievable. Pt-Rh catalyst showsbetter carbonyl reduction than Pd-Rh catalyst. However, each of the three way catalysts is less efficient thanZrO2 catalyst. ZrO2 catalyst used in series with Pt-Rh catalyst shows the highest percentage reduction informaldehyde concentration. Pt-Rh catalyst pair is effective in CO mitigation than Pd-Rh pair. The percentagereduction for HC and NOx is comparable for both. Pt-Rh also depicts better carbonyl reduction ability. ZrO2 isa better choice than noble metals in terms of availability and cost. Moreover it features a selective naturetowards oxidation of aldehydes. Thus, Pt-Rh in combination with ZrO2 becomes technologically effective andeconomically viable choice.KEYWORDS: Biodiesel-Ethanol-Diesel, carbonyl emissions, catalytic converter. I. INTRODUCTIONThe global energy crisis, increasing prices of conventional fuels and increasingly stringent pollutionnorms have led to a greater focus on development of alternative fuels. A study has shown that (Jian-wei, Shah, and Yun-shan, 2009) due to several benefits in terms of fuel economy, power output andemissions, diesel engines rule over the fields of commercial transportation, construction, andagriculture [3]. Biodiesel Ethanol Diesel (BE-Diesel) blends have been considered as potentialalternative fuels for diesel engines due to their renewable property, friendliness to environment andenergy values comparable to fossil fuels. Studies have revealed that (Panga et al., 2006b) biodiesel 254 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963can be used successfully as an amphi-phile to stabilize ethanol in diesel and the biodiesel–ethanol–diesel (BE–diesel) blend fuel can be stable well below sub-zero temperatures [1]. It was found that(Panga et al., 2006c; Ren et al. 2008a) particulate matters (PM), total hydrocarbon (THC) and COwere substantially reduced for BE–diesel in comparison with fossil diesel [1, 4, 15]. However theunregulated carbonyl emissions (aldehydes and ketones) due to the use of the said blends have seldombeen investigated. Partial oxidation of hydrocarbons and alcohols in the blend is considered as themajor cause of carbonyl emissions (Wagner and Wyszynski, 1996a) [5, 15].The atmospheric carbonyls in urban area are mainly emitted by vehicular exhaust (Panga et al.,2006d; Ren et al. 2008b) [1, 4]. Some carbonyls such as formaldehyde, acetaldehyde, acrolein andmethyl ethyl ketone are mutagenic, and even carcinogenic to human body as listed by USEnvironmental Protection Agency (EPA) (Roy, 2008) [6]. Furthermore, carbonyls play a critical roleon the troposphere chemistry. They are important precursors to free radicals (HOx), ozone, andperoxy-actylnitrates (PAN) (Panga et al., 2006e; Ren et al. 2008c) [1, 4]. Even short term exposure toaldehyde vapours show effect of eye and respiratory tract irritancy in humans. Also, the report on thehealth effects of aldehydes in ambient air (2000b) states that inhaled aldehydes are likely to causeteratogenic effects [2]. Thus mitigation of carbonyls emitted from diesel engines fuelled using BE-diesel blends is vital. To establish a reduction system, it is important to develop a technique foreffective measurement of carbonyl emissions.Among all the engine hardware auxiliary systems, the catalytic converter is considered to have thehighest aldehyde reduction potential (Wagner, Wyszynski, 1996b) [5]. Relevant literature regardingthe use of catalytic converters for carbonyl emission reduction is reviewed. The aldehyde reductionpotential of oxidation catalysts with gasoline fuelled engines is 97-100 per cent. Three-way catalystshave nearly the same reduction potential (90-100 per cent). Aromatic aldehydes were completelyremoved by the catalyst, while highest inefficiency was shown for formaldehyde (three-way catalystand oxidation catalyst) [7]. (Cooper, 1992). According to Weaver (1989) the catalytic convertersapplied to natural gas fuelled engines reduced formaldehyde by 97-98% [8]. As per the study byColden and Lipari (1987), for methanol fuelled engines the conversion efficiency has been 98 per centfor a three-way catalyst (platinum-palladium-rhodium) and 96 per cent for an oxidation catalyst(copper chrome base metal) [9].Catalyst efficiencies for methanol fuelled diesel engines wereanalyzed by McCabe et al., (1990a) [10]. The use of Platinum palladium oxidation catalyst resulted inan increase in the aldehyde emissions instead of reduction. The effect was attributed to the oxidationof methanol to aldehyde caused by the platinum palladium catalyst. The substitution of palladiumwith silver resulted in a reduction of aldehyde emissions owing to high selectivity of the catalyst toconvert formaldehyde to carbon-dioxide and water (McCabe et al., 1990b) [10]. The conventionalnoble metal catalysts in general have oxidative action on both alcohol and carbonyls and thus there isa strong likely hood of the exhaust leaving the catalytic converter still containing significantaldehydes produced through partial oxidation of the alcohol(Wagner, Wyszynski, 1996c) [5]. Thus theneed for amendments in the existing catalytic converter technology for engines using alcohol fuel isrealized. In the present paper, focus has been laid on the development and testing of a catalyticconverter which would enable the reduction of carbonyl emissions for a diesel engine using BE-dieselfuel. Mitigation of CO, HC’s and NOx has also been considered along with aldehydes and ketones.High performance liquid chromatography, HPLC followed by spectroscopy has been used by severalresearchers for measurement of carbonyl compounds in the engine exhaust [11]. Trapping methodusing a bubbler and a suitable solvent had been used by Lipari and Swarin (1982).Trapping methodsusing Di nitrophenyl hydrazine (DNPH) cartridges have also been reported [12]. The cartridge iseluted using suitable solvent and the sample is available as a liquid to be injected for HPLC (Yacoub,1999). In the present research, a bag sampling method suggested by Roy (2008) [6] is used to trapcarbonyls in engine exhaust. HPLC-UV technique is implemented for sample analysis.II. CATALYTIC CONVERTER DEVELOPMENTIn case of ethanol blended fuels, the oxidation of ethanol and formation of aldehyde and oxidation ofaldehyde proceed according to the following formulae: C2H5OH (From BE-Diesel) + O2 Aldehydes + H2O --------- (1) Aldehydes + O2 H2O + CO2 --------- (2) 255 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963The conventional noble metal catalysts progress the reactions (1) and (2) side by side but the reaction(1) may occur rapidly leading to great amount of aldehyde. It was realized that Zirconium Oxide(ZrO2) is highly selective in its action and progresses the reaction according to formula (2)considerably faster than reaction (1). Thus selective oxidation of aldehyde is attained relative toalcohol and an excellent removal of aldehydes is achievable. When the proposed catalyst is placeddownstream of a conventional three way catalyst, HC, CO, NOx may be controlled at the upstreamside of the arrangement and the carbonyls can be selectively controlled at the downstream side asshown in figure 1.0. Fig 1.0 Schematic - catalytic converter arrangement.Metallic substrates (stainless steel) having volume 150cc are used for the Zirconium oxide catalyst.Following properties of ZrO2 are considered during catalytic converter development. Table 1.0 Properties of ZrO2 Sintering Temperature >10000C Melting Point ~27000C Chemical inertness and corrosion resistance up-to ~20000CLoading the powder at 200gm/litre of substrate volume is intended. Zirconium oxide powder, due tothe lack of adhesiveness required for coating on the substrate, is mixed with Al2O3 and other suitablebinding agent and chemicals to prepare slurry and is then coated on to the mesh surface. The slurrycomposition is as depicted in table 2.0. Table 2.0 Slurry Composition Component Name Function Weight % Zirconium oxide powder Catalyst 30 Alumina Binding agent 20 Concentrated HNO3 Control over pH and viscosity 0.5 Reverse osmosis water Solvent 50The components are mixed and slurry is agitated to attain desirable particle size distribution whilemonitoring continuously the pH and viscosity. Slurry thus obtained is used to wash coat the substrate.The substrate is then subjected to Vacuuming Process to attain a uniform thickness of the coating.Coated substrate is then taken through a drying cycle involving temperatures of the order of 4000Cand eventually subjected to adhesion loss test at temperatures up-to 10000C.The adhesion loss isrecorded to be 2.13% which is within allowable limits.Readily available, conventional three way catalytic converters loaded with Platinum-Rhodium (Pt-Rh)and Palladium-Rhodium (Pd-Rh) on metallic stainless steel substrate (150cc) are used for HC, CO andNOx mitigation. Fig 2.0 shows the catalytic converters used. 256 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963 Fig 2.0 Pt-Rh catalytic converter (Left), ZrO2 catalytic converter (Right)III. EXPERIMENTAL SET-UP AND SAMPLING PROCEDURE Fig 3.0: Schematic- Sampling setupFig. 3.0 shows schematic of experimental set-up modeled in CATIA for collection of exhaust sample.Direction Control Valves and Non Return Valves are used to guide exhaust flow. The lowtemperature engine exhaust (at low load conditions) can directly be collected without allowing it topass through heat exchanger. The high temperature engine exhaust (at high load conditions) is cooled(lower than the sustainable temperature of equipment in setup) by using a coiled heat exchanger,before its collection in the sampling bag. The volume flow rate of exhaust is measured by gasrotameter. Tedlar gas sampling bags, made from a special inert material are used for the collection ofthe sample. The sample collected is subjected to chemical treatment to stabilize the carbonyls in thecollected exhaust. Thereafter the stabilized solution is analyzed to understand the carbonylconcentration using HPLC-UV technique.Particulate filters are used in the actual set-up to prevent clogging in the ancillary equipments. RTDand K type thermocouples are used to determine the temperature of the exhaust gas at differentlocations in the set-up. The image of actual setup is shown in figure 4.0. 257 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963 Fig 4.0: Image of sampling setupThe catalytic converter substrates are 64 mm in diameter and 60 mm in length. The diameter of theexhaust pipe from engine is 40mm. Converging and diverging nozzles are manufactured to connectthe exhaust pipe to catalytic converters. Catalytic converters are fitted inside an insulated tin canninghaving diameter slightly greater than outer diameter of the substrate. Two or more converters, (whenused) are placed end to end in the canning with a small gap (around 2mm) in between. Thearrangement is shown in figure 5.0. Fig 5.0: Image- catalytic converter arrangement in exhaust line ‘Kirloskar’ make naturally aspirated DI diesel (shown in fig 6.0) Gen-set/Tractor engine is used fortrials. Fig 6.0: Image-Engine Set-up 258 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963Its specifications are given in table 3.0 Table 3.0 Engine SpecificationsRated Power 27.9 KWRated Speed 1500 rpmCooling System Water cooledDynamometer Hydraulic ControlledLubrication Inbuilt engine operated pumpNo of cylinders 3Compression Ratio 18.10Nozzle Diameter 0.20 mmInjection Time 210 After BTDCFuel Injection Pressure 500 BarsThe BE-Diesel fuel used has following composition and properties (Refer Table 4.0). Table 4.0 Fuel composition and PropertiesEthanol 30% by volumeBio-diesel 20% by volumeDiesel 50% by volume 0Density at 15 C 835 kg/m3Kinematic Viscosity at 400C 2.4 cStCalorific value 38965 kJ/kgThe engine exhaust, after flowing through the catalytic converter arrangement is partly divertedtowards the gas sampling line. All trials are conducted at 20kg dynamometer load (mean load in fivemode test) and 1500rpm engine speed. Different catalytic converter arrangements using Pt-Rh or Pd-Rh and the specially manufactured ZrO2 catalyst are used. Gas is sampled in Tedlar bags of 5 literscapacity to measure the concentration of carbonyls. 0.5 grams of DNPH in 400ml of ACN with fewdrops of perchloric acid is used as absorbing solution. 20ml of the said DNPH solution is inserted inthe bag before sampling. A flow rate of 1 LPM is maintained at the bag inlet by using a flow controlvalve and sampling is carried for 4 minutes. 4 liters of exhaust gas is thus collected in the bag asshown in fig 7.0. It is ensured that the ambient conditions during the collection of samples fordifferent trials are constant. The collected sample is thoroughly shaken to homogenize the mixture andaccelerate the formation of respective hydrazones. To stabilize the mixture, it is cooled at -300C foraround 30 minutes in refrigerator. The stabilized condensate is then collected in small vials for furtheranalysis. An AVL make gas analyzer (refer Fig 8.0) is used to observe and record concentrations ofHC, CO and NOx. Fig 7.0: Exhaust collection in Tedlar Bags Fig 8.0: Gas Analyzer 259 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963IV. SAMPLE ANALYSIS:The exhaust sample collected is analyzed using High Performance Liquid Chromatography (HPLC-UV) technique [13, 14]. The HPLC system used is shown in Fig 9.0.Chormatographic conditions aregiven in table 5.0. Fig 9.0 HPLC-UV apparatus Table 5.0 HPLC Chromatographic conditions: Parameter Remarks Description Column: Analytical column: Inertsil C-18(ODS), 4.60mm*250.00mm,5 micron particle size Column oven Ambient temperature 32 degrees. temperature Detector: UV- Visible 360nm wavelength (Lambda maximum) Sample: 20 micro-liters Flow-rate: 1mL/min Mobile phase ACN HPLC grade HPLC system LC-10AT vp, Shimadzu make(Japan) Data acquisition PC controlled Spinchrome softwareThe results obtained from the HPLC-UV apparatus consist of a chromatogram showing peaks (Fig10.0) and numerical data sheet corresponding to the retention time and peak area (table 6). Table 6.0 Numerical Data sheet-HPLC Sr. No. Retention. Area Height Area [%] Height W05 Time [min] [milli- [milli- [%] [min] Volt-sec] Volts] 1 2.823 46.014 7.35 1 1.2 0.11 2 3.01 3899.952 428.713 99 98.8 0.12 Total 3945.996 433.921 100 100The retention time is the characteristic of the compound and the peak area is a direct measure of theconcentration.4.1 Preparation of standards:The standard solution of Formaldehyde Hydrazone is analyzed using HPLC-UV to get its retentiontime and concentration. According to the molar equilibrium from the chemical reaction, a standardsolution having a concentration of 500µg/ml (w/v) of formaldehyde hydrazone in acetonitrile isprepared and analyzed. The results obtained are of the following nature (refer fig. 10.0): 260 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963 [mV] c:docum ents and settingsvitchem desktopsr km ech_chem _pro2011for m aldehyde_hydr azone_365nm 600 3.010 2 500 400 Voltage 300 200 2.823 1 100 0 0 1 2 3 4 [min.] Time Fig. 10.0 Formaldehyde standard chromatogramSimilarly, peaks were obtained for acetaldehyde and acetone standard solutions.4.2 Analysis of samples:The samples collected in the vials after refrigeration are injected in the HPLC-UV apparatus for theiranalysis. Three iterations of the same sample are carried out to verify the reproducibility of peaks.Arithmetic mean of the corresponding three areas is considered while calculating the concentration.The mean retention time obtained is used to identify the compound.For the standard solution: Formaldehyde + DNPH Hydrazone + Water 1 mole 1 mole 1 mole 1mole 30 gms 198gms 210gms 18gmsThe molar mass ratio mf= 30/210 =1/ 7Mean area Am= 3751.6395; Mean retention time Tm= 3.0065 minFor sample:Area of peak in standard solution chromatogr am concentrat ion of standard solution = Area of peak in sample chromatogr am concentrat ion of hydrazone in sample Concentration of formaldehyde in liquid sample is related to the concentration of hydrazone asfollows: Concentrat ion of hydrazone in sample ∗ volume of absorbing solution ∗ mf Concentrat ion of formaldehy de in sample = Volume of exhaust sample collectedDepending on volume of exhaust sampled, the concentration (weight per liter of exhaust) iscalculated. V. RESULTS AND DISCUSSION:The results of the Raw Sample from the HPLC analysis are as are shown in Fig 11.0 261 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963 Solvent Peak [mV] C:Docum ents and SettingsVITCHEMDesktopSRKM ech_Chem _Pro2011trials on june 9-10CHROM ATOGRAM SRAWJUNE 13 new syr Raw 00 600 2.937 2 500 400 Voltage 300 200 2.237 1 100 0 0 1 2 3 4 [min.] Time Fig. 11.0 Raw sample chromatogramThe retention time of this peak is comparable to the retention time of formaldehyde standard solution.Minor deviation is due to the slight variation in back pressure. Solitary formaldehyde peak isobtained. Peaks of acetaldehyde and acetone are not obtained due to their lower concentrations thanthe limit of detection, at the given loading condition. The data is sufficient to understand thequalitative change in carbonyl concentration with the use of several catalytic converter arrangements.Exhaust samples with different catalytic converter arrangements are collected and analyzed. Retentiontime of each arrangement is close to that of formaldehyde standard. Sample chromatograms for twoarrangements are given in figures 12.0 and 13.0. [mV] C:Docum ents and SettingsVITCHEMDesktopZrO2 3 250 2.933 200 150 Voltage 100 50 1.953 0 0 1 2 3 4 [min.] Time Fig. 12.0 Chromatogram-One ZrO2 catalytic converter sample [mV] 200 C:Docum ents and SettingsVITCHEMDesktopPt-Rh=Zr 6 2.957 150 Voltage 100 50 1.933 2.243 0 0 1 2 3 4 [min.] Time Fig. 13.0 Chromatogram-ZrO2 CATCON in series with Pt-Rh catalytic converterChromatograms for seven different arrangements are obtained and formaldehyde concentrations areexamined (Table 7.0 and Fig 14.0). Percentage reduction for each of the arrangements is thenanalyzed (Refer fig. 15.0). CO, HC and NOx conversion efficiencies for conventional three waycatalyst (Pt-Rh and Pd-Rh) are determined (refer fig. 16.0). It is observed that their efficienciesremained constant irrespective of combination with specially designed ZrO2 catalyst. 262 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963 Table 7.0 HCHO concentrations for various catalytic converter arrangementsSr. Catalytic converter Mean retention Mean peak area Concentration ofNo. arrangement time of the injected formaldehyde in the corresponding to the of the injected sample in sample in µg/l of exhaust injected sample sample in sec Milli-Volt-sec 1 Raw (No CATCON) 2.9434 5333.993 580.3169 2 Pd-Rh 2.93 2897.93 315.2831 3 Pt-Rh 2.9266 2645.003 287.7656 4 Pd-Rh/ZrO2 2.9543 2350.9683 255.7758 5 ZrO2 2.931 2283.46 248.4312 6 2*ZrO2 2.932 2272.859 247.2779 7 Pt-Rh/ZrO2 2.9276 2166.016 235.6538 Concentration of HCHO in 600 500 400 Concentration µg/l of HCHO in 300 µg/l of exhaust 200 100 0 CATCON arrangement Fig. 14.0 Concentration of formaldehyde for different CATCON arrangements Pt-Rh/ZrO2 CATCON arrangement 2*ZrO2 % Reduction in HCHO ZrO2 concentration Pd-Rh/ZrO2 Pt-Rh Pd-Rh 0 20 40 60 80 100 % Reduction in HCHO concentration w.r.t. raw Fig. 15.0 Percentage reduction of formaldehyde in the exhaust 263 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963 Concentration of HC in Concentration of HC in 30 30 Raw 20 20 ppm ppm 10 Pt-Rh Raw 10 Pd-Rh 0 0 HC HC Concentration of CO in % COncentration of CO in 0.04 0.04 0.03 0.03 % volume volume 0.02 Raw 0.02 Raw 0.01 Pt-Rh 0.01 Pt-Rh 0 0 CO CO Conncentration of NOx in 1000 Conncentration of NOx in 1000 ppm ppm 500 Raw 500 Raw Pt-Rh Pd-Rh 0 0 NOx NOx Fig 16.0: Pt-Rh and Pd-Rh HC,CO and NOx reduction.Formaldehyde concentration obtained for one ZrO2 catalyst sample is significantly lower than rawemissions. The effect is attributed to the selective nature of ZrO2 catalyst in oxidation of carbonyls.Added ZrO2 catalyst showed further reduction. Thus with optimum loading and surface areaimprovement methods, better results are achievable.Pt-Rh catalyst shows better carbonyl reduction than Pd-Rh catalyst. However, each of the three waycatalysts is less efficient than ZrO2 catalyst. This could be due to non-selective oxidative nature ofthese catalysts where-in alcohol vapors in exhaust are partially oxidized to carbonyls therebyincreasing their concentration.ZrO2 catalyst used in series with Pt-Rh catalyst shows the highest percentage reduction informaldehyde concentration. Pt-Rh is effective in CO mitigation than Pd-Rh. The percentagereduction for HC and NOx is comparable for both. Pt-Rh also depicts better carbonyl reduction ability.The better overall catalytic properties of Pt-Rh than Pd-Rh may be due to contamination of palladiumcatalyst by some elements in exhaust of BE-diesel fuelled engine (Johnson Matthey website, 2011)[13]. The unaffected carbonyls are selectively taken care of by the ZrO2 catalyst downstream.Increasing Platinum loading in conventional catalyst could give better results for carbonyl mitigation.However, ZrO2 is a better choice than noble metals in terms of availability and cost. Moreover itfeatures a selective nature towards oxidation of aldehydes. Thus, Pt-Rh in combination with ZrO2becomes technologically effective and economically viable choice.VI. CONCLUSIONSAll the significant contributions listed in section 2 were experimentally verified and results arereported. Formaldehyde was the most dominant carbonyl at the given loading conditions. Other 264 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963aldehydes and ketones could be detected using HPLC equipment with better limit of detection orcollecting higher volume of exhaust. Zirconium oxide shows effective catalytic activity towardscarbonyl mitigation, better than conventional three way catalysts. Combination of Platinum Rhodiumand Zirconium Oxide catalyst enables significant reduction of carbon monoxide, hydrocarbons,nitrogen oxides together with aldehydes and ketones. Platinum-Rhodium catalyst plays a role inmitigation of CO, HC, NOx while aldehydes are taken care of by ZrO2 downstream. The saidcatalyst combination is an important development in catalytic converter technology, both due to itstechnological and economic features, especially in case of alcohol fuelled engines. It promotes the useof renewable fuels such as BE-diesel, methanol-diesel, methanol, gasoline and so on. Improvedcatalyst efficiencies are achievable with optimum catalytic converter design. ZrO2 catalyst used inseries with Pt-Rh catalyst shows the highest percentage reduction in formaldehyde concentration. Thefuture work is to be carried out with different arrangements of catalytic converter modules of lengths(currently used in series) in series and parallel. The problem of insulation of the converter andleakages at joints while making series units of standard lengths of converters currently available for 2wheelers for use in 4 wheelers needs to be further investigated. The selection of parameters inidentifying different percentage is done from existing test methods and preparation of catalystcombinations by experience, during this work and procedure for selection needs to be investigated.REFERENCES[1] Xiaobing Panga, Xiaoyan Shia, Yujing Mua, Hong Hea, Shijin Shuaib, Hu Chenb, Rulong Lib,Characteristics of carbonyl compounds emission from a diesel-engine using biodiesel–ethanol–diesel as fuel,Atmospheric Environment, Volume 40, Issue 14, pp2567-2574, May 2006.[2] Report on the Health Effects of Aldehydes in Ambient Air, Prepared for COMEAP – the Department ofHealth Committee on the Medical Effects of Air Pollutants. Government of United Kingdom, December 2000.[3] Asad Naeem Shah, Ge yun-shan, Tan Jian-wei, Carbonyl emission comparison of a turbocharged dieselengine fuelled with diesel, biodiesel, biodiesel-diesel blend, Jordon Journal of Mechanical Industrial.Engineering, Vol. 3, pp 111-118, Number 2, 2009.[4] Y Ren, Z-H Huang, D-M Jiang, W Li, B Liu, and X-B Wang, Effects of the addition of ethanol and cetanenumber improver on the combustion and emission characteristics of a compression ignition engine, Journal ofAutomobile Engg, Vol-222, Issue 6, pp 1077–1087, 2008.[5] T Wagner, M. L. Wyszynski, Aldehyde and Ketones in Engine Exhaust Emissions- A review, Journal ofAutomobile Engg, Vol-210, Issue D2, pp 109, 1996.[6] Murari Mohan Roy, HPLC analysis of aldehydes in automobile exhaust gas, Energy conservation andmanagement, 49, pp 1111-1118, 2008.[7] Cooper B., The future of catalytic systems. Automotive Engineering, Volume 100, Number 4, 1992.[8] Weaver, C.S. Natural gas vehicles-a review of the state of the art. SAE paper 891233, 1989[9] Lipari, F. and Colden, F. L. Aldehyde and unburned fuel emissions from developmental methanol-fuelled2.51 vehicles, SAE paper, 872051, 1987.[10] McCabe, R. W, Kmg, E. T., Watkins, W. L. and Gandhi, H. S. Laboratory and vehicle studies of aldehydeemissions from alcohol fuels, SAE paper 900708, 1990.[11] Lipari F and Swarin S, Determination of Formaldehyde and other Aldehydes in Automobile Exhaust with2, 4 DNPH method, Journal of Chromatography, 247, pp 297-306, 1982.[12] Y Yacoub, Method Procedures for sampling Aldehyde and ketones using 2,4 DNPH-a review, Journal ofAutomobile Engineering. Volume 213, Issue 5, pp 503-507, 1999.[13] Ronald K. Beasley, Sampling of Formaldehyde in Air with Coated Solid Sorbent and Determination byHigh Performance Liquid Chromatography, Analytical Chemistry, Volume 52, No. 7, June 1980 pp-1111.[14] Xlanliang thout, Measurement of Sub-Parts-per-Billion Levels of Carbonyl Compounds in Marine Air by aSimple Cartridge Trapping Procedure Followed by Liquid Chromatography, Journal of Environ. Sci. Technol.1990, 24, pp1482-1485.[15] D. B. Hulwan Study on properties, improvement and performance benefit of diesel,-ethanol-biodieselblends with higher percentage of ethanol in a multi-cylinder IDI diesel engine, IJAET, Volume I, Issue II, July-Sept., 2010, pp 248-273.[16] Technical discussions, Johnson Matthey website- http://www.matthey.com/, 2011. 265 Vol. 1, Issue 5, pp. 254-266
    • International Journal of Advances in Engineering & Technology, Nov 2011.©IJAET ISSN: 2231-1963Author’s Biographies:Abhishek Balkrishna Sahasrabudhe: Bachelor of Mechanical Engineering, University of Pune.(Vishwakarma Institute of Technology). Departmental academic topper. Now, pursuing Graduatestudies in Mechanical Engineering at Stanford University, California. Graduate Research Assistantat High temperature Gas dynamics (HTGL) Laboratory-Stanford University. Research Interests:Engines and energy systems, Pollution mitigation, Alternative and renewable energy, combustionand kinetics, Computational fluid flow and heat transfer, mechatronics / design.Sahil Shankar Notani: Bachelor of Mechanical Engineering, University of Pune (VishwakarmaInstitute of Technology). Presently working at Emerson Innovation Center as an R&D Engineer,Keeps interest in learning computational domains for design and optimization of mechanicalsystems, Aspires to pursue Masters in Engineering from a renowned university in the said domain.Tejaswini Milind Purohit: Bachelor in Mechanical Engineering, University of Pune.(Vishwakarma Institute of Technology). Presently working as a Graduate Engineering Trainee atMahindra & Mahindra Ltd, Wishes to pursue Masters in the field of mechanical engineering.Tushar Patil: B. E. Mechanical from the University of Pune (Vishwakarma Institute ofTechnology). Current occupation: Working as an Engineering services person at Jubilant lifesciences, Aims to pursue Masters in Business Administration from the best university.Satishchandra V. Joshi: Satishchandra V. Joshi is working as professor of MechanicalEngineering at Vishwakarma Institute of Technology, Pune in Maharashtra, India. He earned hisPh. D. from Indian Institute of Technology Bombay at Mumbai, India. Professor Joshi has vastexperience in Industry, teaching and research. He has published papers in International, Nationaljournals and conferences numbering 15. Professor Joshi has worked on projects of World Bank andGovernment of India on energy aspects. 266 Vol. 1, Issue 5, pp. 254-266